The X-37B Orbital Test Vehicle
on the runway during post-landing operations on Dec. 3, 2010, at Vandenberg Air
Force Base in California

The U.S. Air Force has kept an unmanned space shuttle in orbit for the
past two years, and it seems no one without security clearance knows what it’s
been doing up there.

The X-37B
Orbital Test Vehicle, which can enter orbit and land without human
intervention, is scheduled to touch down this week—the best guess is sometime on
Tuesday—at Vandenberg Air Force Base, northwest of Santa Barbara, Calif. The
landing will mark completion of the program’s third and longest mission, which
was launched on Dec. 11, 2012. The Air Force has two such spacecraft for these
low-earth orbit missions, all of which are classified, as are the precise launch
and landing times.

“The mission is basically top secret,” says Captain Chris Hoyler, an Air
Force spokesman. The X-37B program came from technologies developed by
Boeing
(BA),
NASA, the Air Force, and the Defense Advanced Research Projects Agency (Darpa).

In a testing procedure, the X-37B Orbital Test Vehicle taxis on
the flightline in June 2009 at Vandenberg AFB, Calif.

X-37B as a test platform “to advance the state of the art” in areas
such as “thermal protection systems, solar power systems, thermal control,
environmental modeling, autonomous control and landing, and control algorithms.”

The one definitive thing the Air Force will say about the X-37B is
that it has no plans to develop a manned version. The spacecraft measures 29
feet long and 9.5 feet high, about one-fifth the size of the retired NASA space
shuttles that seem to have inspired its appearance. It has a payload bay that
opens in space, just like the larger space shuttles. The first X-37
mission ended in December 2010 after almost eight months in orbit.

The U.S. Air
Force X-37B Orbital Test Vehicle during encapsulation within the
United Launch Alliance Atlas V on Feb. 8, 2011, at Astrotech in Titusville, Fla.

The X-37B “is clearly a military program that no one has necessarily
felt the need to justify politically,” says Laura Grego, a senior scientist in
the global security program at the Union of Concerned Scientists. She says the
spacecraft’s likely missions could probably be handled by satellites and other
platforms at lower cost to taxpayers.

Marco Caceres, a space analyst with Teal Group, says the Air Force is most
likely interested in having a surveillance platform that can “maneuver in orbit
faster” than satellites. Darpa is also working on a new hypersonic “spaceplane”
called the XS-1 that could offer quick access to space and launch
payloads into orbit for less than $5 million per flight. “Quick, affordable, and
routine access to space is increasingly critical for U.S. Defense Department
operations,” the agency said in its
call for
proposals for the spacecraft late last year.

Air Force officials scheduled the launch of the X-37B on April
21, 2010, at Cape Canaveral Air Station, Fla.

Regardless of what the X-37B does in space, the Air Force appears to
be
planning a future for the program. Earlier this month, NASA said it had
agreed to let the Air Force use two former space shuttle hangars at Kennedy
Space Center in Florida to prepare the X-37B for launches. The craft is
sent into orbit atop the Atlas V rocket, designed and built by the United Launch
Alliance, a Boeing-Lockheed
Martin (LMT) joint venture. The Air Force also wants to be able to
land the craft in Florida, which, as with the space shuttle program, saves a
cross-country return trip and makes it easier to prepare for the next flight.

As with many top-secret Pentagon programs, speculation has flourished online
about what the government is doing with the spacecraft. Theories range from
surveillance to, well, more surveillance involving satellites that are so
secretive they can only be released in space. Others have suggested the craft is
the platform for a new generation of kinetic weapons that can be used from
space. (Here’s
a look at one theoretical space weapon at the center of speculation by
defense and tech nerds for more than a decade.)

The X-37B Orbital Test Vehicle on the runway during post-landing
operations Dec. 3, 2010, at Vandenberg Air Force Base, Calif.

Lest one scoff at the notion, the U.S. military has been testing such
hypersonic weapons for several years from earth-based launch systems. Moving
one into space may pose additional technical and financial challenges, but it’s
hardly impossible. “The basic problem with these ‘orbital bomber’ and
Starship Trooper ideas is that they would cost trillions of dollars—all to
deliver a thimbleful of force,” former RAND Corp. analyst John Arquilla
wrote.

One even farther-fetched theory? The Air Force is testing the craft so
it can eventually drop special-forces soldiers from space to anywhere on the
planet, within minutes.

17 October 2014Secret space plane lands at US air force base after unknown two-year missionResembling a small space shuttle, the X-37B landed in southern California after 674 days in orbit on a secret mission
Associated Press in Vandenberg Air Force Base, California
The Guardian

A top-secret space plane landed Friday at an air
force base on the southern California coast.

The plane spent nearly two years circling Earth on a
classified mission. Known as the X-37B, it resembles a
mini space shuttle.

It safely touched down at 9.24am Friday, officials
at Vandenberg Air Force Base said.

Just what the plane was doing during its 674 days in
orbit has been the subject of sometimes spectacular
speculation.

Several experts have theorized it carried a payload
of spy gear in its cargo bay. Other theories sound
straight out of a James Bond film, including that the
spacecraft would be able to capture the satellites of
other nations or shadow China’s space lab.

In a written release announcing the return of the
craft, the air force only said it had been conducting
“on-orbit experiments”.

The US air force’s first unmanned
re-entry spacecraft landed at
Vandenberg Air Force Base in California.Photograph: US AIR FORCE/Reuters

The X-37B program has been an orphan of sorts,
bouncing since its inception in 1999 between several
federal agencies, Nasa among them. It now resides under
the air force’s rapid capabilities office.

The plane that landed Friday is one of two built by
Boeing. This is the program’s third mission, and began
in December 2012.

The plane stands 9.5ft tall and is just over 29ft
long, with a wingspan under 15ft. It weighs 11,000lbs
and has solar panels that unfurl to charge its
batteries once in orbit.

The air force said it plans to launch the fourth
X-37B mission from Cape Canaveral, Florida, next year.